Generally, a conventional coaxial speaker includes a frame and a magnetic element in the form of an annular magnet mounted to a rear end of the frame. In the frame, there are a voice coil, a voice coil support, a diaphragm, and a suspension. A coaxial tweeter is mounted to a front center of the speaker. With the above arrangements, the coaxial speaker can cooperate with other related electronic apparatus to output sound.
In the above speaker structure, there is a gap between the coaxial tweeter and the voice coil support. When the coaxial speaker is used outdoors, external moisture tends to invade the speaker via the gap between the coaxial tweeter and the voice coil support and reach into the annular magnet. The moisture accumulated in the annular magnet over a long time will affect the normal operation of the polar plates in the annular magnet and the voice coil to even shorten the service life of the coaxial speaker.